Process of preparing a permanent and spinnable solution in the cupricammonia process



.was spun.

- normal tempernture.

UNITED STATES PATENT orr PAUL HERMANN MINCK. OF PETERSDORF.

ice;

GERMANY, ASSIGNOR, mi MESNE ASSIGN- MENTS, TO THE CHEMICAL FOUNDATION. INC. A CORPOR ATION OF DELAWARE.

PROCESS OF PREPARING A PERMANI SN '1 AND SPINNABLE SOLgllION: IN CUPRIG- R0 Drawing.

Specification of Application filed July 28.

To all whom it may concern:

' Be it known that I, PA UL HERMANN Mmcn, a citizen of the free town of Hamburg, residing at the village of Petersdorf, in the Kingdom of Prussia, Germany, have invented certain new and useful Im rovements in a Process of Preparing a ermanent and Spinnable Solution in the Cupric-Ammonia Process, of which the following is a specification.

In preparing cellulose solutions by the cupric ammonia process it was heretofore necessary to maintain a temperature of 4 cent.- The finished solution had, further more to .be kept at such temperature until it Later it was proposed to employ sugar in preparing permanent cellulose solutions eta It has been disclosed;' to embodycarbohydrates in 'cupric ammonia to treat'such solutions with tetrahydric or higher alcohols such as dulcitol or manitol; a modification has also been disclosed consisting in the organic substances of the cellulose or cupric ammonia mixture being mixed with each other before further treatment.

-The processes quoted show a degree of uncertainty re rding the selection of the organic adm xtures and their proper use in preparing cellulose solutions, and in fact such uncertainty did exist up to a short time ago, and it has been only by the experiences gained in course of many years that the full explanation of the complicated reactions occurring in the solution of cellulose by means of cupric ammonia has been found.

It was found that for the practical application of. the process on a commercial scale certain kinds of'sugar were preferable. as these could he obtained of the necessary purity, so as to ensure'thcir rapid combination within the matter to hespun and to prevent a coloration v0i the cellulose. hoth points on which the spinninp capacity and the appearance of the finished product depends.

It has been claimed that the spinning materials are more permanent and that the threads obtained therefrom have a greater Strength and elasticity beside a very fine silk gloss. These claims are however only fulfilled, if in preparing the solution the re spective sugars are correctly selected with regard to their characteristic or specific AMMONIA PROCESS.

Letters Patent. Patented JIIIY 4:, 1922.

1918. Serial No. 246,419.

elfect and if they are employed in given, ac-

such means, does not show any improvement as compared with spinning materials' prepared, .without sugar; possibly a greater strength might be shown but such increase in strength would be accompanied by serious disadvantages. An addition -of35%;01 'glucose is by far too great and will result in suclnquantities of slimy substances in the solution. that the filtercells, throu h which the material must pass, will soonlbe" ll'ed and spinning nozzles would soon be stopped for" t ie same reason. It has therefore found that it is impossible' -to spin -such materials on a commercial oasis,- Besides the spun product will have a deep to the impurities contained in'the u' and such color can not be'remove "The gloss of the spun threads isals o seriously impaired the slimy matter drym' surface. due to the presence of the molecu es'oithe glucose, since this serves to )revent cohesion of the cellulose molecules. he su'gar"should not form a physical part 'of the 'finished threads, but should enter into 4 bination with the hydrate of cellulose, it is therefore quite wrong to employ sugar in large quantities. as it: then will only 'act as a detrimental ballast in the spinning solutions.

It has now become has only chemical duties, and these in en tirely diil'erent senses, which form t heifeature of the present invention. l i

The first duty or effect of the sugar consists in reducing the cu lulose, both of which show during the process of manufacture of the spinninggsolu'tion up sugannre best suited which will have a strong 105 reducing effect in small quantities and at a. normal temperature. a

The sugars belonging to this class Ire of yellow color owing {l6 I olitheir 1e strength of the threafis sufl'ers chemical 9 1!; as apparent that the sugar pric salt and the celsolubility of the cupric 1 is considerably greater the g'roup of grape sugars, such as glucose and the saccharides which all-correspond to the formula C,H O,. Amongst these .glucose and invert sugar an equimolecular mixture ofglucose and fructose are the best suited. Of these latter kinds of sugar {'73 (a quarter per cent) of the weight of thecellulose will be sufiicient to ensure a strong and efi'ective action against the oxidizing tendency of the cupric salt and the cellulose during the preparation of the spinning. solution. S inning solutions prepared in such manner will stand comparatively high temperature and are very' permanent, if kept in closed es s- Difliculties have, however, been eneoun tered in s inning such solutions and in the Qfluality o the woven material'made there fig; and as Spinn g opacity 1 mm. The reduction of the cupric salt and gttua eellulose,by means of the luoose is ac- }:oinpariied by a dehydrationw iich impairs the 'homogemty of the spinning material demands a perfect homogeneit When emerging flit-bridge firifiee of' t iethnozzles the dfine t re 17i -not pos$ess, 'e necessary uctility tadam u er foie readilybreak in the coagulation batli'glthe finished thread is besides hard audijiosses'ses littlefip'ldgjlty This may be explained by theIact-th'al: the original cellulose cannot, in consequence of tlle dehydrating effect of the sugar-ab sorltiinf'fitfl' fiissolved state sufiicient-chemi'- b iled water; so as to be precipitated? ,"livliien the"solution ;'is-spun in t e spinning bath as ac full l'iydrateof cellulose. in whit} 1} fonm'only th .s no material will receive its favorable Zua ities as regards strength, elasticity and gloss.

For ob yiatiug such difiiculties other sugais are employed, which, contrary to gluand invert sugar have a' decided by drating'efi'ect on cellulose and cupric salts, whilst abthe same, time they prevent an oxi- .dation thereof. These sugars belong to the group of cane sugars, the (llSlttClltllhlLSJlHll of these .refined beet sugar has been found to be the one most preferable. The di-' saccharidesthus perform a special duty in forming cellulose solutions, which is directly contrary to that of gra'pesugar. A permanent solution of cellulose treated with .very small quantities of glucose will become spinnahle only after, by the addition of disacrlulrides the hydration of the q-llulose liasheen secured. Itappears as if this efl'ect is obtained by catalysis, us about 2". of the weight of the cellulose will, on the average, suflice to convert the latter into the desired h 'dcatc. The condition of the cellulose may a so determine the amount of-disaccharido tolxnusedu ('ellu use which has been little or not at all decom msed utill require only a small amount of d1sacchar1de.-

As the formula for cane sugar and cellulose hydrate is the same, viz. ll ll this mutual effectof the substances cu ployi-d may be theoretically explained. In the new process the volume of sugar employed (a total of approximately 21%) is so small that the spinning solution can by no means be spoiled by the same.

According to the facts ascertained it is impracticable to substitute cane sugar for the grape sugar. Theoretically it is possible to substitute cane sugar for tho gra 1e sugar, but this is not practicable because t e reducing died; of cane sugar will start at higher temperatures only, andwill even then amountto only th of the reducing power of grape sugar. If the reduction of the cupric salt and the cellulose necessary for the permanence of the spinning material were to be secured by cane sugar, such large quantities of the latter would have to be used that'the spinning capacity of the masses would be rendered doubtful by the considerable nantitles. of unoxidized slimy matter resu ting from the sugar. Theclaims hereinafter specified are based upon the accurate recognition of the different effects of the two kinds of sugar described in the foregoing statement. By working according to the specifications heretofore disclosed it was not -.possible to obtain a permanent and spinnable cellulose solution by means. of sugar.

I claimz.

q 1 The'procesi of preparing spinnable' I {cupric-ammoniacellulose solutions consistfing in the reduction of the cupric salts res- 'ent in the solution and dehydration o the Cellulose by means of sugars of the gra srigar group and the hydration of the cel ulose by sugars of the cane sugar group, the amount of such sugars being not less than one-quarter of one per cent and not more than (u-o-aml one-half per cent based on the weight of cellulose employed. a .2. The prmrcss of preparing spinhable cupir-ununonia-rcllulose solutions consisting in the reduction of the cupric salts present in the solution and dehydration of the (alluloso by means of glucose and the hydration of the cellulose by sugars of the cane sugar group. the amount of such sugars being not less than one-quarter of one more than two and one'hal per cent based on the weight of cellulose employed;

3. The process of preparing 'spirinable cuprio-ammonia-rellulose solutions; consisting in the reduction ofthe cilpric salts resent in the solution and dehydration o the cellulose by means of sugars of the grape sugar group and the hydration of the cellulose by sucrose, the amount of such sugars being not less than one-quarter of one per cent and not more than two and one-half 'pcl' centbased on the yiieight of cellulose employed.

r cent and not 4. TIN! process of proapafing #sfiihhahlehenh in the'solution and dehydration of th 5 nuprir-a nnno'nia? :ellnlose. -solutions -consist mg in the reductnon of.the'cupr1e salts pregnl in the SOhltlOXl nnd dehydration of the cellulose by means of glucose and the hydration of thc cellulos by sucrose, the amount of such sugars being not less than one-quar- 1e; of one pgr cent and not more than two and one-half Yer cent based on thenweight of cellulose amp 0 yed.

' l 5. The process of preparing spinnahle cupnic-ammoniawelluhisejisolutions consisth in thqxreduction' of the cupric salts prescellulose by means of glm-ose employing about one qu'arwi' of onv per cent of. the

weight of cellhlose and tho hydrationnf the,

x-vllnlosc by sucros employing almuthi'o per a (3. A cupric -anunonia-ci-lhllosu solution containing about one quarter of one? per 0entha sed on film weight of this m-llulose of glm ose and about two per cent of sucrose.

In testimonywvhel'eof l have aflixed my signaturm PAUL HERMANN MINCK. 

